Effects of repealing the motorcycle helmet law in Michigan.

BACKGROUND: In 2012, Michigan repealed its universal helmet law. Our study assessed the clinical impact of this repeal.

METHODS: Our trauma database was queried retrospectively for 2 motorcycle riding seasons before and 3 seasons after repeal. On-scene death data was obtained from the Medical Examiner.

RESULTS: Helmet use in hospitalized patients decreased after the helmet law repeal. Non-helmeted patients had a significant increased rate of head injury. Non-helmeted patients were more likely to die during hospitalization. While, helmet use and drugs/alcohol status significantly affected the risk for head injury, only drug/alcohol had a significant effect on overall mortality.

CONCLUSIONS: Following helmet law repeal, helmet use has decreased. Helmet status and drug/alcohol use was found to significantly increase risk of head injury. Although overall mortality was only affected by drug/alcohol use, non-helmeted patients did have a higher inpatient mortality. These findings deserve furthermore study and may provide a basis for reinstating the universal helmet law.